spi_flash.c

This reverts commit c56ae751.

Once the 'Quad Enable' bit is cleared in their Enhanced Volatile
Configuration Register (EVCR), Micron memories expect ALL commands to use
the SPI 4-4-4 protocol. Commands using SPI 1-y-z protocols are no longer
accepted.

Within the reverted commit, the write_evcr() function is implemented using
the spi_flash_write_common(), which is a shortcut for the
[ spi_flash_cmd_write_enable(), spi_flash_cmd_write(),
spi_flash_cmd_wait_ready() ] sequence.

Since the internal state of the Micron memory has been changed when the
spi_flash_cmd_write() function completes, the later call of the
spi_flash_cmd_wait_ready() function fails.

Indeed the SPI controller driver is not aware of the SPI protocol switch.

Further patches will fix the support of Micron QSPI memories.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[Rebase on master, use JEDEC_MFR(info) in place of idcode0]
Signed-off-by: Jagan Teki <jagan@openedev.com>